Novel systems and methods for non-destructive inspection of airplanes

ABSTRACT

A method for managing an airplane fleet is described. The method includes: (i) developing a gold body database for an airplane model for each non-destructive inspection system implemented to detect defects; (ii) inspecting, over a period of time, a plurality of candidate airplanes of the airplane model, using different types of non-destructive inspection systems and the gold body database associated with each of the different types of non-destructive inspection systems, to identify defects present on the plurality of candidate airplanes; (iii) repairing or monitoring defects detected on the plurality of candidate airplanes; (iv) conducting a trend analysis by analyzing collective defect data obtained from inspecting of plurality of candidate airplanes; and (v) maintaining the airplane fleet, which includes plurality of candidate airplanes, by performing predictive analysis using results of trend analysis.

RELATED APPLICATIONS

The present application is a divisional of and claims priority to U.S.patent application Ser. No. 13/876,849, filed Mar. 28, 2013, which is anational stage entry of PCT Application No. PCT/US2011/053190, filedSep. 26, 2011, which further claims priority to U.S. ProvisionalApplications having Ser. Nos. 61/387,980 and 61/387,976, both of whichwere filed on Sep. 29, 2010, which is incorporated herein by referencefor all purposes.

FIELD OF THE INVENTION

The present invention relates to novel systems and methods for managingairplane fleets. More particularly, the present invention relates tomanaging airplane fleets using non-destructive inspection methods andpredictive analysis.

BACKGROUND OF THE INVENTION

Frequent tragedies in airplane transportation have caused concern overthe ability of airlines to evaluate the airworthiness of airplaneswithin their respective fleets. As airframes age, characteristics ofmaterials, which make up airframe components, change due to stresses andstrains associated with flights and landings. Moreover, there is a riskthat a state of the airframe material may go beyond the point ofelasticity (i.e., the point the material returns to its originalcondition) and extend into the point of plasticizing or worse, beyondplasticizing to failure. As a result, periodic inspections and testingare conducted on airplane components during the airplane component'slife cycle. Such inspections and testing are mandated by governingbodies and are largely based on empirical evidence.

Inspections and testing of airplanes are bifurcated into two areas:destructive testing and nondestructive inspection (NDI), nondestructivetesting (NDT) or nondestructive evaluation (NDE). “NDI,” as this term isused hereinafter in the specification, encompasses the meanings conveyedby NDT and NDE, as those are described above. The area of destructivetesting, as the name implies, requires the airplane component underscrutiny to be destroyed in order to determine the quality of thatairplane component. This can result in a costly endeavor because anairplane component that may have passed the procedure is destroyed, andis no longer available for use. Frequently, where destructive testing isdone on samples (e.g. coupons) and not on actual components, thedestructive test may or may not be reflective of the forces that theactual component could or would withstand within the flight envelope ofthe airplane.

On the other hand, NDI has the obvious advantage of being directlyapplied to actual airplane components or sub-components in their actualenvironment. Several important methods of NDI that are performed in alaboratory setting are listed and summarized below.

Radiography involves inspection of a material by subjecting it topenetrating irradiation. Although effective damage detection has beendone using neutron radiation, X-rays are the most familiar type ofradiation used in this technique. Most materials used in airplanecomponent manufacturing are readily acceptable to X-rays. In someinstances, an opaque penetrant is needed to detect defects.

Real-time X-rays, which are frequently used as part of recent inspectiontechniques, permit viewing the area of scrutiny while doing a repairprocedure. Some improvement in resolution has been achieved by using astereovision technique where the X-rays are emitted from dual deviceswhich are offset by about 15 degrees. When viewed together, these dualimages give a three-dimensional view of the material. Still, theaccuracy of X-rays is generally no better than plus or minus 10% voidcontent. Neutrons (N-ray), however, can detect void contents in the plusor minus 1% range. The difficulty in implementing radiography raisessafety concerns because a radiation source is being used. Nevertheless,in addition to detecting internal flaws in metals and compositestructures using conventional non-radiography related methods, X-raysand neutrons are useful in detecting misalignment of honeycomb coresafter curing, blown cores due to moisture intrusion, and corrosion.

Ultrasonic is the most common non-destructive inspection method fordetecting flaws in composite materials. The method is performed byscanning the material with ultrasonic energy while monitoring thereflected energy for attenuation (diminishing) of the signal. Thedetection of the flaws is somewhat frequency-dependent and the frequencyrange and scanning method most often employed is called “C-scan.” Inthis method, water is used as a coupling agent between the sendingdevice and the sample. Therefore, the sample is either immersed in wateror water is sprayed between the signal transmitter and the sample. Thismethod is effective in detecting defects even in samples that aresubstantially thick, and may be used to provide a thickness profile.C-scan accuracies can be in the plus or minus 1% range for void content.A slightly modified method call L-scan can detect stiffness of thesample by using the wave speed, but requires that the sample density beknown.

Acousto-ultrasonic, another non-destructive inspection method, issimilar to ultrasound except that separate sensors are used to send thesignal and other sensors are used to receive the signal. Both sensorsare, however, located on the same side of the sample so a reflectedsignal is detected. This method is more quantitative and portable thanstandard ultrasound.

Acoustic emission, a yet another non-destructive inspection method,involves detecting sounds emitted by a sample that is subjected tostress. The stress can be mechanical, but need not be. In actualpractice, in fact, thermal stresses are the most commonly employed.Quantitative interpretation is not yet possible except forwell-documented and simple shapes (such as cylindrical pressurevessels).

Thermography (sometimes referred to as “IR thermography”) is yet anothernon-destructive inspection method that detects differences in relativetemperatures on the surface undergoing inspection. Differences inrelative temperatures on the inspected surface are produced due to thepresence of internal flaws. As a result, thermography is capable ofidentifying the location of those flaws. If the internal flaws are smallor far removed from the surface, however, they may not be detected. Inthermography, there are generally two modes of operation, i.e., anactive and a passive mode of operation. In the active mode of operation,a sample is subjected to stress (usually mechanical and oftenvibrational) and the emitted heat is detected. In the passive mode ofoperation, the sample is externally heated and the resulting thermalgradients are detected.

Optical holography, a yet another non-destructive inspection method,uses laser photography to give three-dimensional pictures, which arecalled “holography.” This method detects flaws in samples by employing adouble-image method, according to which two pictures are taken whilestress is induced on a sample between the times when a picture is taken.This method has had limited acceptance because of the need to isolatethe camera and the sample from vibrations. However, it is believed thatphase locking may eliminate this problem. The stresses that are imposedon the sample are usually thermal. If a microwave source of stress isused, moisture content of the sample can be detected. For compositematerial, this method is especially useful for detecting debonds inthick honeycomb and foam sandwich constructions. A related method iscalled shearography. In this method, a laser is used with the samedouble exposure technique as in holography where stress is appliedbetween exposures. However, in this case an image-shearing camera isused in which signals from the two images are superimposed to provide aninterference pattern and thereby reveal the strains in the samples.According to this method, strains are detected in a particular area, andthe size of the pattern can give an indication of the stressesconcentrated in that area. As a result, shearography allows aquantitative appraisal of the severity of the defect. The attribute ofquantitative appraisal, relatively greater mobility of shearography overholography, and the ability to stress the sample using mechanical,thermal, and other techniques, has given this method wide acceptancesince its introduction.

Unfortunately, current commercial industry inspection and repair methodssuffer from several drawbacks. By way of example, the above describednon-destructive inspection methods are largely limited to laboratoryanalysis. The current commercial industry inspection and repair methodsare inefficient, costly and not standardized. As another example, theseinspection and repair methods have seen little or no changes in the past20 or 30 years and have not solved the “Aging Airplane” safety problems.As it stands now, inspection of airplane components are limited to the“Tap Test,” visual inspection, and Eddy Current analysis. Furthermore,inspection timetables are developed and updated primarily as a functionof anecdotal evidence, all too frequently based on airline catastrophes.

Despite a wealth of diagnostic tools mostly available in laboratorysettings for detecting defects, what is, therefore, needed are novelsystems and methods for effective airplane fleet management and that donot suffer from the above-described drawbacks encountered by the currentairplane inspection methods and systems.

SUMMARY OF THE INVENTION

In view of the foregoing, in one aspect, the present invention providessystems and processes that use one or more NDI systems, which revealdifferent types of defects on the same components.

In another aspect, the present invention provides a method for managingan airplane fleet. The method includes: (i) developing a gold bodydatabase for an airplane model for each non-destructive inspectionsystem implemented to detect defects; (ii) inspecting, over a period oftime, a plurality of candidate airplanes of the airplane model, usingdifferent types of non-destructive inspection systems and the gold bodydatabase associated with each of the different types of non-destructiveinspection systems, to identify defects present on the plurality ofcandidate airplanes; (iii) repairing or monitoring defects detected onthe plurality of candidate airplanes; (iv) conducting a trend analysisby analyzing collective defect data obtained from inspecting ofplurality of candidate airplanes; and (v) maintaining the airplanefleet, which includes plurality of candidate airplanes, by performingpredictive analysis using results of trend analysis.

The construction and method of operation of the invention, however,together with additional objects and advantages thereof, will be bestunderstood from the following descriptions of specific embodiments whenread in connection with the accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view inside a robotic envelope of some majorcomponents of a fleet management system, in accordance with oneembodiment of the present invention.

FIG. 1A shows one robotic movement system, in accordance with oneembodiment of the present invention, through the X-axis.

FIG. 2 is a front view of a fleet management system, in accordance withpreferred embodiments of the present invention, for managing acommercial airplane fleet.

FIG. 2A shows an attachment, in accordance with preferred embodiments ofthe present invention, to a rail in the X-axis as shown in FIG. 1A.

FIG. 3 is a side view of a commercial airplane fleet management systemshown in FIG. 2.

FIG. 3A shows a vertical mast support, in accordance with preferredembodiments of the present invention.

FIG. 4 is a side view of an N-ray system, in accordance with preferredembodiments of the present invention.

FIG. 4A shows a section of the mast, in accordance with preferredembodiments of the present invention.

FIG. 5 is a side view of an X-ray system, in accordance with preferredembodiments of the present invention.

FIG. 5A shows some major components of a mast drive system, inaccordance with preferred embodiments of the present invention.

FIG. 6 is a side view of an N-ray yoke, in accordance with oneembodiment of the present invention.

FIG. 7 is a side view of an X-ray yoke, in accordance with oneembodiment of the present invention.

FIG. 8 is a side view of an adjustable lower leg of an N-ray yoke, inaccordance with preferred embodiments of the present invention.

FIG. 9 is a side view of an adjustable lower leg of an X-ray yoke, inaccordance with preferred embodiments of the present invention.

FIG. 10 is a side view of pitch, rotate and yaw of a laser yoke, inaccordance with preferred embodiments of the present invention.

FIG. 11 is a front view of a laser addressing the airplane, inaccordance with preferred embodiments of the present invention.

FIG. 12 is a front view of a laser addressing an airplane and theconfiguration of the laser and the airplane is shown in accordance withpreferred embodiments of the present invention.

FIG. 13 is a top view of a fleet management system, in accordance withpreferred embodiments of the present invention.

FIG. 14 is a process flow diagram for an airplane fleet managementprocess, in accordance with preferred embodiments of the presentinvention.

FIG. 15 is a process flow diagram for a method of developing a gold bodydatabase, in accordance with preferred embodiments of the presentinvention, of a particular airplane model and that is developed for eachNDI system implemented to detect defects.

FIG. 16 shows a plan view of an exemplar airplane having variouscomponents and sub-components.

FIG. 17 shows a scan plan, in accordance with preferred embodiments ofthe present invention, for inspecting an exemplar right leading edge boxof an airplane stabilator using a Maneuverable N-ray Radiography System(“MNRS”).

FIG. 18 shows a scan plan, in accordance with preferred embodiments ofthe present invention, for inspecting an exemplar right leading edge boxof an airplane stabilator using a Maneuverable X-ray Radiography System(“MXRS”).

FIG. 19 shows a defect map, according to preferred embodiments of thepresent invention, prepared by overlaying defects found by NNRS and MXRSinspection of an exemplar right leading edge box of an airplanestabilator.

FIG. 20 shows an X-ray and N-ray imaging configurations, according topreferred embodiments of the present invention, implemented to obtain avolumetric measurement.

FIG. 21A shows a defect map, according to preferred embodiments of thepresent invention, prepared by overlaying defect (e.g., moisture,corrosion and voids) detection carried out by MNRS and MXRS inspectionof an exemplar horizontal stabilator.

FIG. 21B shows an exemplar data summary of various defects found in anexemplar horizontal stabilator.

FIG. 22 shows an exemplar table resulting after conducting a trendanalysis for defective components, which require repair or disassembly.

FIGS. 23A and 23B shows a process flow diagram, in accordance withpreferred embodiments of the present invention, for managing orrepairing defects found in an airplane's component or sub-componentusing an NDI system and when the repair requires removing the defectivecomponent or sub-component from the airplane.

FIGS. 24A and 24B shows a process flow diagram, in accordance withpreferred embodiments of the present invention, for managing orrepairing defects found in an airplane's component or sub-componentusing an NDI system and when the repair is carried out on an intactairplane (i.e., the defective component or sub-component is not removedfrom the airplane).

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the following description, numerous specific details are set forth inorder to provide a thorough understanding of the present invention. Itwill be apparent, however, to one skilled in the art that the presentinvention is practiced without limitation to some or all of thesespecific details. In other instances, well-known process steps have notbeen described in detail in order to not unnecessarily obscure theinvention.

The present invention recognizes that currently, commercial safetyintegrity is continually compromised by not determining the extent of anairplane's structural defects. To this end, the present invention isdirected to systems and processes that perform NDI of airplanes andcomponents or sub-components thereof. Certain key aspects of the presentinvention involve systematic and automated inspection methods andapparatuses coupled with comparison to a gold body database (also knownin the art as a “reference” or “standard”) to allow for predictiveanalysis that is based on trend analysis of defects found in a pluralityof candidate airplanes. A candidate airplane, as the term is used inthis specification, refers to an airplane that undergoes inspection fordefect detection. An airplane fleet includes a plurality of candidateairplanes.

NDI systems and methods of the present invention are contained inside orcarried out in a structure, preferably configured as an enclosure. Thestructure includes walls, a ceiling, and a floor. A hangar door entranceis defined in a wall. Moreover, the structure utilizes concrete asshielding to attenuate the emission of radiation to the outside of theenclosure. In certain embodiments of the present invention, varioussafety measures may be implemented. By way of example, interlocks areprovided to prevent the emission of radiation when personnel might beendangered because a door to a room, containing excessive amounts ofradiation, is opened. Other measures, such as key controls and passwordauthentication may be provided to prevent emission of radiation or otherpotentially hazardous activities, such as motion of robotic systems,without approval of authorized personnel. Radiation monitoring and alarmsystems are preferably provided to detect abnormal radiation levels andprovide warning.

For each NDI system or method implemented to detect defects, corbels areprovided to support multiple robots. Walls, ceiling, and hanger doorentrance are designed to support the corbels, permitting translation(e.g., along X-axis) across the items under inspection, testing orevaluation. Corbels designed to accommodate structural loading whilemaintaining accuracy and repeatability of robot position over six axesof movement, which are described below, within a narrow range oftolerances better than plus or minus about 0.250 inches, and preferablybetter than plus or minus about 0.120 inches. They accommodatestructural loading of various types, e.g., floor loading, wind loading,loading in earthquake zones and loading from the mass of the robots.

In preferred embodiments, inventive NDI systems for inspecting anairplane component or sub-component include a beam arrangement forsupporting and allowing translation of a carriage. The beam is mountedon rails which are attached to the corbels by the means of end trucks,providing movement along the length of the facility or X-axis. Thecarriage moves along the length of the beam providing movement in theY-axis. A telescoping tube or mast is attached to the carriage in avertical position, providing movement in the Z-axis. At the bottom ofthe mast, three axes of movement are provided, i.e., pitch, rotate, andyaw of the yoke to which the inspection apparatus is attached. Thetranslations permit the system to scan an intact airplane to thecomponent level or the sub-component level. The carriage is coupled to amast structure for supporting and allowing translation of a yoke.

The mast comprises a plurality of tubes that can move telescopically toprovide a large range of motion in a vertical direction, and at the sametime, supporting large amounts of mass. In one embodiment of theinvention, the beam arrangement is located overhead, for example, nearthe ceiling of the building. The building and beam arrangement form agantry for supporting the carriage as well as the yoke which is mountedon the mast. In a preferred embodiment of the present invention, theyoke includes two members that may be extended telescopically to adjustthe throat depth of the yoke.

In another embodiment of the present invention, the yoke is configuredto accommodate surfaces that change a camber of the wing. In particular,configurations of the first member support a beam source and the secondmember supports an imaging device. In an alternative embodiment of thepresent invention, the mast supports a laser ultrasonic scanner. In thisembodiment, a laser ultrasonic scanner is attached to the mast of theinspection and testing apparatus and configured with rotational axes toallow scanning in a plurality of directions across complex surfaces ofthe airplane, including its components or sub-components.

Real-time X-ray radiography is accomplished in motion utilizingmulti-axis movement of robots to scan at a rate that is between aboutone and about three inches per second and at a magnification that isbetween about three times and about five times. Any pendulum or swayeffect at the bottom of mast (with yoke attached) causes a real-timeradiography image to unfocus, or in the alternative, get distorted andbecome unreadable to an operator. The problematic pendulum or swayeffect is believed to be caused by two separate resonating frequencies,i.e., the fundamental frequency of the robot based upon the mass andrigidity of the robot structure, and the robot mounting to the housingfacility which has its own resonating frequency when one ore more robotsare in motion. Providing two separate parallel bridges mounted to singleend trucks with carriage straddling both parallel bridges and the mastlocated between the two separate bridges yields acceptable results solong as the length of the bridge does not exceed a certain length,typically about 180 feet. Providing a single rail bridge typicallypermits a length of the bridge not to exceed about ninety-six feet.

Existing hangar structure may be modified or new facilities may be builtto attenuate any pendulum effect and resonating frequencies that coulddistort robotic inspection readings. Facility modification or new designwould be based upon three separate requirements, i.e., seismic, resonatefrequency of the facility with one or more robots in motion, and therobotic envelope. Site surveys may determine the seismic activity,ground water location, type of soil, soil compaction and may result inbuilding the facilities foundation as an isolation pad. The resonatefrequency of the facility with the robots in a static position aremodeled to evaluate the pendulum effect of the robots and to determinethe amount of reinforcement of steel and concrete needed to meetfrequency requirements for the facility's bearing walls. It is believedthat as the robots move closer to the hangar door, the pendulum effectsbecome unacceptable. Therefore, appropriate modifications may be made tothe concrete hangar door header, and a lateral tie or footer may beprovided at the ground level. Such modifications rigidify the side ofthe structure containing the hangar door to attenuate any resonatefrequencies to acceptable levels during the airplane inspection usingrobots. The robotic envelope is determined based on the type of airplanethat is subject to inspection within the facility. The envelope isfactored in, and any resonate frequencies are attenuated in order toprovide inspection accuracy and repeatability.

Inspection of airplane wings requires the control surfaces to beextended to allow for a total wing inspection. This wing configurationcauses sharp radial surface turns at the fore and aft ends of the wings'leading and trailing edge surfaces and the inability for a normal“C”-shaped yoke to conform to these areas to perform a total inspectionof the part. The solution to this problem is to provide a modifiedC-shaped yoke with a lower arm having an articulating member, akin to adouble joint, in order to allow the lower arm to tuck underneath thecontrol surface.

When the preliminary designs of the buildings, robots, and end effectorsare completed, modeling of the entire system may be performed to assureaccuracy and repeatability of robot positioning. Oscillatory excitationof the system components resulting from robot motion and accelerationand deceleration may be analyzed. Designs of the system components maybe modified to maximize desirable characteristics, such as accuracy andrepeatability of robot positioning, while minimizing undesirablecharacteristics, such as unwanted oscillatory excitation of systemcomponents.

FIGS. 1-13 described below show various systems and sub-systems used incertain embodiments of the present invention, to implement, among otherthings, the methods of the present invention. A Robotic OverheadPositioner (ROP), (e.g., as shown in FIG. 1) is a gantry robot thatresembles an overhead crane. The ROP allows movement in three lineardirections (i.e., X, Y, and Z) and three rotational directions (i.e.,Yaw, Pitch and Roll described below). Generally, to move in each ofthese directions, it uses a variable-speed DC motor 14 (which is shownin greater detail in FIG. 1A), a gearbox 16, and an encoder 22 includinga drive mechanism 18 having wheels 52. Power to turn the motor (thusmoving the robot) is supplied by a controller 20. Each motor 14 includesencoder 22, which instructs controller 20 regarding distance of travel.Motor 14 also includes a solenoid energized electric disc brake 24,which keeps the robot in a frozen position whenever controller 20 is notsupplying power to motor 14. For each direction robot 12 is capable ofmoving, there is also an absolute-positioning resolver 26, whichinstructs controller 20 regarding the robot's location via encoder 22.Limit switches 28 inside resolver 26 prevent the motor 14 from drivingwheeled drive mechanism 18 beyond its end of travel. Power to motor 14and signals to controller 20 are supplied via cables 32 (as shown inFIG. 1), which are fully insulated and which have military-standardconnectors. As shown in FIG. 1A, heavy-duty frictionless bearings 36 areused throughout, in accordance with one embodiment of the presentinvention, to maximize system reliability.

As shown in FIGS. 1 and 1A, a bridge 38 moves in a first lineardirection (i.e., X-axis) on a runway 40. Runway 40 is made of sets oftwo parallel rails 42 (shown in FIG. 2) mounted on rail ledges 44 (shownin FIG. 2A). FIG. 2 shows one rail 42 on each sidewall 46 (and two rails42 on a central corbel 43) of the inspection bay 48. Rails 42 haveadjusters 50 for leveling and parallel alignment, as shown in FIG. 2A.

Wheels 52, as shown in FIGS. 1A and 2, are designed to support bridgeend trucks 38. A pair of wheels 52 rides on rails 42. Each pair ofwheels has its own motor 14 and its own resolver 26. Bridge 38 enclosesand supports drive mechanism 18. As motor 14 turns, wheels 52 turn,moving bridge 38 back and forth on the rails 42. The dual motor14/resolver 26 scheme enables controller 20 to avoid bridge 38 skewingoff the rail 42. If limit switches 28 in the resolver 26 were to fail,thereby allowing an operator to move bridge 38 to the very end of therails 42, shock absorbers 54 on bridge 38 and end-stops 56 on rails 42prevent bridge 38 from striking walls 58. A crank 59 is provided on eachend of bridge 38 as a manual backup motion system to allow the bridge tomove without motor 14.

FIGS. 1 and 2 show the second linear direction (i.e., Y-axis) where atrolley 60 moves along a span 39 which extends between two rails 42.Similar to X-axis, trolley 60 moves along span 39 in a dependentrelationship, as shown in FIG. 3A. Span 39 is box-shaped and has spacedparallel vertical rails 64 and spaced parallel horizontal rails 68forming an enclosed box. The weight of trolley 60 is bearing on itswheels 52 that ride on opposed outer faces of each vertical rail 64. Asmotor 14 turns, wheels 52 also turn, moving trolley 60 left and right(along Y-axis) on span 39. One wheel set 52 rides on a lower edge of onevertical rail 64 and another wheel set 52 rides on a top edge ofopposite vertical rail 64 to keep trolley 60 (and thus the mast 70) fromtilting. Span 39 preferably has an upwardly projecting central crown 68(as shown in FIG. 2) of about one-half inch when unloaded and bowsone-half inch downwardly when trolley 60 moves to the middle of span 39.Thus, span 39 is, therefore, normalized (i.e., level) along a length. Iflimit switches 28 in resolver 26 were to fail, allowing an operator tomove trolley 60 to the end of rails 42, shock absorbers 54 on span 39and end-stops 56 on the span's ends prevent trolley 60 from strikingwalls 58. A crank 62 is provided on each trolley 60 as a manual backupsystem to allow reorientation of trolley 60 along span 39. The trolley'sdrive is similar to that shown in FIG. 1A.

The third linear direction (i.e., Z-axis) moves mast 70 on trolley 60 upand down via positioner 92, which is shown in FIG. 5A. Mast 70 ispreferably capable of hoisting at least 5000 pounds, and is designedsuch that the failure of any single part of the system will not causeits sensor array, located at the free end of mast 70, to fall to thebottom of mast travel. Mast 70 is a box-shaped inner telescoping tube 74with wheels 76 on an inner surface of box-shaped outer tube 78 riding onrails 80 as shown in FIG. 4A. Mast 70 is hoisted by dual cables 84(shown in FIGS. 4A and 5A) and has two drums 86 (only one is shown tosimplify illustration). As motor 14 turns, each drum 86 deploys a cable84, hoisting inner tube 74. Each drum 86 has a brake 88 mounted to itsdrive shaft 89 to prevent tube 74 from falling if one brake 88 shouldfail. A load sensing mechanism 90 embodied as an overload clutch isprovided on hoisting system brake 88 to stop the mast if a sensorsupporting yoke 100 (e.g., as shown in FIG. 2) should catch on anobject, as it is hoisted up or down or if there is a system overload.This load sensing mechanism 90 will also stop positioner 92 when onecomponent of the hoist system quits operating. For a backup system, eachcable/drum system is capable of hoisting the mast at full load. If thehoist were to over-speed, another sensor 94, monitoring amperage wouldagain perform to trigger an emergency stop. A crank 79 of FIG. 1 isprovided on each mast 70 as a manual backup motion system.

Three rotational axes are incorporated into each inspection yoke 100, asshown in FIGS. 6 through 9. Yoke 100, as mentioned before, is a C-shapedstructure with an adjustable mouth “M” which spans the gap between thesources and receiver. Two X-ray sources 102, 104 (as shown in FIGS. 7and 9), having differing outputs are mounted on top support 101 of yoke100 and an image receiver 106 is mounted on the bottom by arm 103. Yoke100 may also support a collision-avoidance paneling 110. The paneling isa pressure sensitive sheath and is mounted on all lower extremities ofmast 70. The pressure sensitive paneling prevents gross contact with theairplane by mandating a stop signal in the presence of a triggeringpressure. During the scanning of the airplane surfaces, the surface(e.g., wing) is positioned between X-ray sources 102 and 104 and N-raysource 108 (shown in FIGS. 6 and 8) and imager 106. A film source 107may supplement or supplant imager 106.

A first rotational axis 112 (i.e., Yaw) rotates inspection yoke 100 in ahorizontal plane at the bottom of mast 70. A second rotational axis 114(i.e., Pitch) pivots inspection yoke 100 in a vertical plane at thebottom of mast 70. A third rotational axis 116 (i.e., Roll) rotatesinspection yoke 100 in a plane at the end of the pitch axis; this planeis oriented perpendicular to the pitch axis. It is noteworthy that X-raysources 102 and 104, and N-ray source 108 are independently rotatableabout 116 a. Further, each arm (e.g., bottom arm 103 or a side arm) maychange in length as shown by double ended arrows “A” as shown in FIGS. 8and 9. A link 117 connecting bottom and side arms 103, 113 can rotateabout curved arrow “C” to adjust the dimension of adjustable mouth “M,”in conjunction with the telescoping arm's length along arrow “A.”

X-ray sources 102 and 104 are mounted on a movable support such thatonly one of the two sources may be aimed at imager 106 during an imagingevent by rotation about 116 a. This support, called a turret 120 (shownin FIG. 7), is rotated 90 degrees by a stepper motor 122 (shownschematically in FIG. 9). Only the X-ray source aimed at imager 106 maybe activated unless a permanent record is desired via a film source 107which rotates in the place of imager 106. Alternatively, the film source107 can rotate about axis 119 (denoted by arrow 119 a in FIG. 7) toorient the film source 107 to X-ray source 102 and 104. X-ray sources102 and 104 are indexed into position as a function of the object beingscanned, its thickness, and its composition (e.g., composition versusmetal). Imager 106 is an image intensifier, which directs the X-rayimage to the control room operator CRT screen. A bottom arm 103 may alsocarry another type of X-ray imaging system 111 for backscatter X-ray(reverse geometry X-ray). A sender unit 111 is shown mounted adjacentimager 106. Photo-multiplier tubes 109 (shown in FIG. 1) are positionedinside the airplane to receive digital images from sender 111. Receivers105 are also placed on the inside of the production airplane structuresand direct digital imaging information to be sent to the control roomoperators. Yoke manipulative and imaging capabilities specified foreither the N-ray or X-ray could be incorporated in the other.

Because of the varying change in the thickness of airplane internalstructures (such as wings), the X-ray source output (KVP KilovoltagePenetrating Power, MA Milliamps Current) is preferably controlled byrobotic coordinates to allow ramp up or ramp down of X-ray penetratingpower. This allows clear and precise imaging. It also allows an operatorto focus attention to the viewed images and not constantly adjustingoutput due to the change in the airplane structure material thickness.More importantly, each and every airplane is inspected based on the samesettings, conditions and a relevant gold body database.

Yoke 100 also contains a heat gun 150, somewhat like a hair dryer. Thisis used on both the X-ray and N-ray yokes to allow an operator to verifyand distinguish the presence of moisture, water or fuel inside thealuminum or composite bonded structure. Current industry NDI methods andsystems cannot distinguish the difference between moisture and sealant.Once a defect area is detected by either an X-ray or N-ray inspectionsystem or method, heat is applied by the yoke's heat gun 150 to thatspecific area. Heat out generation is monitored by an infrared pyrometer151 in order not to exceed a limit, preferably 160 degrees Fahrenheit,on the structure where the heat is applied. If moisture is present, theapplied heat causes migration of the fluid away from the heat source dueto expansion of the air within the heated structure area. Heat imagesare taken before and after heating. Alternate “before and after” imagesflash on the operator's CRT screen and image picture subtraction isaccomplished. The difference allows the operator to watch moisturemigration. This procedure is important in locating water entry pathswithin the airplane structure or component.

A laser ultrasonics (“laser UT”) apparatus, 130 is also mounted togantry robot system 12. Like yoke 100, apparatus 130 (shown in FIG. 10)is coupled to a carriage 132 (shown in FIG. 2) and a mast 134 mounted tothe carriage 132 with rotational axes as described for the previoustrolley and mast. Laser UT apparatus 130 allows movement in X-axis(along line L), and Y-axis (up and down along line G), and rotationalmovement (e.g., about arrows 112, 114, 116) by using stepper motors 135.The rotational movement of the laser UT apparatus allows it to reachunderside areas of the fuselage while being support by gantry robotsystem 12 that is above the fuselage, as shown in FIGS. 10, 11 and 12. Amirror 136 of FIG. 10 receives laser energy “L” from within housing 130and distributes the energy on the scanned surface by mirror rotation,indexing and mast rotation and scanning, as shown in FIG. 12. Reflectedlaser light provides further diagnostics.

A laser UT gantry robotic system is provided for inspection of bothintact airplane and components removed from the airplane. In preferredembodiments of the present invention, component imaging systems such asX-ray, N-ray and laser UT are utilized for pre-inspection of airplanespare components, as well as post-inspection of repaired componentsremoved from the airplane to ensure adequate repair process andprocedures.

The embodiments of present invention include robotic imaging inspectionmethods and systems, such as real-time X-ray, N-ray and laser UT. Whenused separately, certain imaging inspection methods find certainairplane structural defects. According to certain embodiments of thepresent invention, N-ray imaging inspection methodology locates andimages structural integrity defects such as one selected from a groupconsisting of internal moisture, corrosion, internal fuel leaks, andvoids in sealants. Similarly, real-time X-ray imaging inspectionmethodology finds and images structural integrity defects such as oneselected from a group consisting of moisture, corrosion, cracks, fatiguedamage, collateral damage, flaws, deformation, and foreign objects.Laser UT inspection methodology finds and images structural integritydefects such as one selected from a group consisting of disbond,delamination, impact damage, material life, porosity and voids.

Defects are preferably evaluated against a predetermined accept/rejectcriteria to determine corrective maintenance and repair actions, asexplained below in connection with a step 2310 of FIG. 23A. In certainpreferred embodiments of the present invention, defects are monitoredover time to determine the defect's growth in length, width and depth. Abaseline may be accomplished using X-ray, N-ray and laser UT volumetricmeasurement techniques, and by identifying size (length, width, anddepth) and location of each defect in all components of an airplane.This method provides laminography views through the wing or anycomponent part to locate exact position of a defect within multiplelayers of a component's structural material. The defect may beidentified in multiple material layers existing between the component'sinner most layer and outer most layer of material. By way of example,the method provides two dimensional and three dimensional laminographyviews of a disbond or void within a component's multi-layer compositematerial to determine length, width and depth of the defect at aspecific X-axis, Y-axis and Z-axis position within the material andbetween specific layers of a component's composite material.

The laser UT methodology locates defect regardless of a composite ormetal structure's configuration. When used in combination on any givenairplane or component, or when monitoring a partial or complete airplanefleet or partial or complete fleets of like airplanes, various types ofstructural defects and discrepancies may be identified on acomponent/sub-component or on a series of multiple components at asingle location or on multiple locations on each component/sub-componentwith high precision to delineate a defect or deficiency trend within thecomponent/sub-component or series of components/sub-components. Forexample, the defects or deficiencies may be further analyzed andidentified by the components′/sub-components' part number, serial numberand use on a given airplane's tail number. Each defect's ordiscrepancy's size may be recorded and tracked by inspection number,number of flying hours, number of takeoffs and landing cycles and numberof missions during the component's life cycle. In certain embodiments ofthe present invention, each defect's or discrepancy's growth in size isrecorded and tracked by date and time, inspection, maintenance andrepair location, inspection number, number of flying hours, number oftakeoffs and landing cycles and number of missions during thecomponent's life cycle.

Future structural defects and deficiencies may be formulated andpredicted on a component-by-component basis and may be based on defectgrowth within a component. Furthermore, a defect growth rate within anairplane component may be predicted, which in turn may restrict anairplane fleet's maximum flight speed to inhibit further defect growth.Predictive analysis may also be used to estimate the time betweenmaintenance for the component, inventory requirement to replace orrepair the component or parts within the component, and associatedworkflow days and budget requirements. Structural problems may beformulated and predicted by model and series of airplane, by matchingcomponents' part number and serial number to airplanes' tail number inthe airplane fleet. An airplane component's part number, and serialnumber, and historical inspection, maintenance and repair data iscaptured, entered or downloaded and stored by date and time, inspection,maintenance and repair location, inspection number, number of flyinghours, number of takeoffs and landing cycles and number of missions onan a non-volatile, solid state computer chip containing flash memory andwireless Blue Tooth or other form of wireless communications that isembedded in the component. The computer memory chip is readable by awireless communication data capture and display device without airplaneor component disassembly.

In accordance with embodiments of the present invention, laser UTutilizes a pulsed laser to introduce an ultrasonic sound wave intocomposite or metal material. A pulse laser source is moved along anairplane or a component part's surface by the means of a translationmirror moving in X and Y position to achieve a roster scanning of theairplane or the component of the airplane. The pulse length for scanning(time the laser beam is on the part's surface) can be accomplished at arate of up to 240 pulses per second. The present state-of-the-arttechnologies are limited to surface scanning, and they do not ablatecomposite materials or surface coatings.

In the current manufacturing process of composite materials to achieve adesired shape, a bond former is utilized to nest composite cloth orprepreg resin systems. This bond former is made of metal or compositematerial and is coated with mold release to allow the newly cured partto be removed without destroying the part or bond former. The moldrelease becomes impregnated into the resin system of the new part andmust be removed prior to application of paint, adhesives or othercoatings to achieve proper bond strength and surface tension foradhesion.

The present state-of-the-art methods of removing mold release or surfacecoatings such as paint is accomplished by manual and mechanical meanssuch as hand sanding or high pressure media blast. These manual andmechanical stripping methods expose the new part's composite fibers toexcessive damage when aggressively attempting to remove mold releasefrom the resin system.

Laser UT to inspect and verify airplane component composite condition ismodified and enhanced, in accordance with certain embodiments of thepresent invention, to include laser ablation to precisely andeffectively remove surface coatings on composite material during theinspection process. This can be accomplished, for example, by increasingthe pulsed laser output, or modifying the length of the pulse, or acombination of modifying laser output and pulse length. Ablation isbased on a gain in power of the light source and pulse rate (pulselength in time on the component's material surface). Ablation power andpulse rate may vary based on the type of material and thickness of thecoating that is being removed. Laser UT can measure a coating thicknessbefore and after stripping the coating. As a result, methods, asprovided by certain embodiments of the present invention, affect theresin system or matrix only, not the composite fibers of the component'smaterial. As such, the integrity of the component is not affected bythis method of coating removal. During manufacturing and repair prior tothe airplane component being placed in service, this method providesprecise stripping of surface coating, a reduction in manufacturing andrepair time, and cost savings during final material surface coatingpreparation, final material surface tension preparation for adhesivebonding application, and material surface coating stripping inpreparation for repair. In-service airplane requires periodicinspection, maintenance and repair which require removal andreapplication of painted or coated services. The method described aboveprovides inspection and removal of paint and other coatings during asingle laser UT inspection application.

Considering the drawings, wherein like reference numerals denote likeparts throughout the various drawing figures, reference numeral 10 ofFIG. 1A is directed to non-destructive inspection and testing systems,according to one embodiment of the present invention, for airplanecomponents and/or sub-components.

Each NDI system discussed above has its own robot. Each individual robothas a “home” position to verify accuracy and to correct possiblerelocated robot movement (such as from earthquakes). An example of thisis the home position fixture for the X-ray and N-ray inspection systems.The home position fixture is preferably inverted “L” shape flat platesteel 180 (which is found in FIG. 2) whose vertical leg 180 b isattached to wall 46 with approximately four feet overhang provided byhorizontal leg 180 a from the wall. The flat steel plate overhanghorizontal leg 180 a is parallel to the concrete facility floor. Asmall, about 0.030-inch hole 181 is drilled through the center of anoverhang plate 180 a. With the X-ray system on, a CRT screen containscrosshairs (like a hunting rifle scope) to locate the crosshairs in thecenter of the overhang hole at 5X geometric magnification. This providesa home position initialization step (calibration) and is preferablyperformed prior to each and every airplane inspection and also for allrobots and each inspection method (X-ray, N-ray and Laser UT). Laseralignment relies on a uniform thickness plate 183 having at least twovariations V₁ and V₂ from the uniform thickness at known locations. Thelaser, when scanning the variations (e.g., a counter-bore), preferablyreflects the known variations as a function of relative length anddistance. In FIG. 2A, rails 42 can be aligned by oval slots 51 allowingmotion of rail 42 relative to its support plate 44. A J bolt supportsrail 42 and plate 44 in wall 58. A threaded free end of J bolt 50includes washers “W” and nuts “N” for vertical and lateral truing.

As previously stated, the present invention has at least one andpreferably three or more robots. The use of multiple robots providesseveral advantages. By way of example, multiple robots allowsimultaneous inspection of several areas of an airplane, therebyreducing the time required to inspect an airplane. As another example,multiple robots avoid the need for a single long supporting beam, whichwould reduce positioning accuracy and repeatability. As yet anotherexample, multiple robots allow each robot to be specifically designed toinspect particular areas of an airplane, thereby allowing accommodationof special attributes of various areas.

Corbels 12, 43 and rails 42 are provided to support multiple robots. Thewalls 58, ceiling 59, and hanger door entrance 61 are designed tosupport corbels and rails, which permit linear translation. The locationof corbels within the structure, e.g., an airplane hanger, is designedto accommodate structural loading (due to weight of the robot, roboticmovement yielding unaccepted resonate frequencies, etc.) whilemaintaining accuracy and repeatability of robot position over six axesof movement within a narrow range of tolerances to plus or minus about0.120 inches. The structure accommodates structural loading of varioustypes, for example floor loading, wind loading and loading from the massof the robots.

The inspection facility is designed to protect personnel from radiationhazards (including X-rays and neutrons). Shielding 63 (of FIG. 2A),including shielding of walls, doors, and windows is provided. Interlocks201 (of FIG. 3) are provided to prevent the emission of radiation whenpersonnel might be endangered, such as when a door is opened. Othermeasures, such as key controls and password authentication are providedto prevent emission of radiation or other potentially hazardousactivities, such as motion of robotic systems, without approval ofauthorized personnel. Radiation monitoring and alarm systems 203 areprovided to detect abnormal radiation levels and provide warning.

One example of a technique used to provide radiation safety even thoughthe walls, doors, ceiling and viewing windows are designed to acceptmaximum radiation at a distance of three feet, and do not allow X-ray orN-ray sources to be aimed at these surfaces. In preferred embodiments ofthe present invention, the robot positioners only allow the radiationsource to be aimed toward concrete bay floor 57, or airplane structure.This is accomplished by programming the robotic movement throughout thefacility. Other than in the scan plan, which is discussed in greaterdetail below, during the airplane inspection operation, the radiationsources are non-operational. This is called the “Robotic Approach.” BothX-ray and N-ray sources are on systems or on/off systems. The on/offsystems may be energized at the beginning of the scan plan inspectionoperation or calibration. Override of this radiation protection systemis accomplished for robot or source maintenance purposes, and controlledby software code known preferably to the first level supervisor andmaintenance personnel.

A method for design of a non-destructive inspection, testing andevaluation system for airplane component having a precision roboticsystem is provided. The dimensional and structural requirements of abuilding are determined, and a preliminary design for the building ismade. The preliminary design for the building is analyzed to identifyany frequencies (earthquake zones) at which such a building mightresonate. For example, a technique such as finite element frequencyanalysis may be employed. Based on the results of the analysis, thepreliminary design of the building may be modified to correct anydeficiencies.

The dimensional, structural, and functional requirements for robots tobe housed within the building are determined, and a preliminary designof the robots is made. The preliminary design of the robots is analyzedto identify any frequencies at which such robots might resonate. Anyinteraction between the resonant frequencies of the building and theresonant frequencies of the robots are analyzed. Based on the results ofthe analysis, the preliminary design of either or both of the buildingand the robots may be modified to correct any deficiencies.

The dimensional, structural, and functional requirements of any endeffectors mounted on the robots are determined, and a preliminary designof the end effectors is made. The preliminary design of the endeffectors is analyzed to identify any frequencies at which such endeffectors might resonate. Any interruption between other elements, suchas the building or the robots, is analyzed. Based on the results of theanalysis, the preliminary design of any or all of the building, robots,or end effectors may be modified to correct any deficiencies.

Another factor to be considered is the type of earthquake region inwhich the facility is to be located. Different earthquake regions mayexhibit earthquakes having different characteristics, for exampleearthquakes have vibration and motion of predominantly a certainfrequency range. This frequency range is determined for the location atwhich the facility is to be located based on geological data. Thepreliminary designs of the building, robots, and end effectors areanalyzed base on anticipated excitation from earthquakes. Based on theresults of the analysis, the preliminary design of any or all of thebuilding, robots, or end effectors may be modified to correct anydeficiencies.

When the preliminary designs of the buildings, robots, and end effectorsare completed, modeling of the entire system may be performed to assureaccuracy and repeatability of robot positioning. Oscillatory excitationof the system components resulting from robot motion and accelerationand deceleration may be analyzed. Designs of the system components maybe modified to maximize desirable characteristics, such as accuracy andrepeatability of robot positioning, while minimizing undesirablecharacteristics, such as unwanted oscillatory excitation of systemcomponents.

FIG. 16 shows a plan view of an exemplar airplane 1600 that is subjectto inspection in the above-described robotic envelope as part of fleetmaintenance. To facilitate discussion, only certain major components andsub-components are described below.

Airplane 1600 includes various component and sub-components. As shown inFIG. 16, airplane 1600 includes components, such as a left wing 1602, aright wing 2602, a left horizontal stabilator or stabilizer 1604 (asthose terms are interchangeably used in the specification), a righthorizontal stabilizer 2604, a left vertical stabilizer 1606 and a rightvertical stabilizer 2606. These components further includesub-components. By way of example, left wing 1602 includessub-components such as a left wing tip 1602 a, a left aileron 1602 b, aleft flap 1602 c. Similarly, right wing 1602 includes sub-componentssuch as a right wing tip 2602 a, a right aileron 2602 b, a right flap2602 c.

As another example, left horizontal stabilizer 1602 includessub-components, such as a left leading edge box 1604 a and a left aftbox 1604 b, and right horizontal stabilizer 2604 includessub-components, such as a right leading edge box 2604 a and a right aftbox 2604 b. Left and right vertical stabilizers 1606 and 2602 includesub-components such as, a left forward box 1606 a, a left torque box1606 b, a left aft box 1606 c, a right forward box 2606 a, a righttorque box 2606 b, and a right aft box 2606 c, respectively.

Exemplar airplane 1600 resembles an F-15 aircraft, but airplane 1600could be any airplane or aircraft and may well include a commercialairplane. Those skilled in the art will appreciate that differentairplanes include different components or sub-components and even ifdifferent airplanes have the same components or sub-components, they mayhave different component or sub-component sizes. By way of example,although an F-15 has left vertical stabilizer (e.g., denoted byreference numeral 1606 in FIG. 16) and right vertical stabilizer ((e.g.,reference numeral 2606 in FIG. 16), a commercial airplane has only asingle vertical stabilizer. The systems and methods of the presentinvention, nevertheless, allow for effective automatic fleet inspectiondespite these different component/sub-component configurations indifferent types of airplanes.

NDI systems and processes of the present invention preferably containfeatures to perform non-destructive inspection and testing of intactairplanes or of components and/or sub-components removed from anairplane. Such inventive systems and methods include a database whichcontains electronic information relating to at least one profile of aprototypical airplane or component (a comparison standard), which ismaintained in an enclosure at constant environmental conditions (e.g.,constant temperature, humidity and pressure).

Although preferred embodiments of the inventive methods and systemsapply to fleet of airplanes, the present invention is not so limited.Methods and systems of the present invention apply to aircrafts andother types of in-flight vehicles (e.g., helicopters, Unmanned AerialVehicles and spacecrafts). The terms “airplane” and “aircraft” have beenused interchangeably in the specification. Furthermore, as the terms“airplane” and “aircraft” are used in the specification, in addition tothe in-flight vehicles mentioned above, they include manned or unmannedvehicles capable of flight by gaining support from air, and spacecraftsthat are capable of sub-orbital or orbital space flight.

FIG. 14 is a process flow diagram 1400 for maintaining an airplanefleet, according to preferred embodiments of the present invention. Anairplane fleet includes a plurality of candidate airplanes. In thisembodiment, process 1400 begins with a step 1402 which includesdeveloping a gold body database for a particular airplane model and foreach NDI system implemented to detect defects. In other words, a goldbody database is developed for a particular airplane model using aparticular NDI system (e.g., an X-ray or an N-ray inspection system). Byway of example, if an X-ray and an N-ray inspection system are used toinspect candidate airplanes of a particular model, then according tostep 1402 a first gold body database is developed for the X-rayinspection system and a second gold body database is developed for theN-ray inspection system. As will be explained later, the gold bodydatabase developed in this step serves as a “reference database,” duringsubsequent inspection or defect analysis steps. A more detailedexplanation of the development of a gold body database is presentedbelow in connection with a description of FIG. 15.

Next, a step 1404 includes inspecting, over a period of time, aplurality of candidate airplanes of the particular model using differenttypes of NDI systems to perform one step selected from a groupconsisting of generating a defect report using different gold bodydatabases associated with each NDI system, and developing a baseline foreach component or each sub-component in the plurality of candidateairplanes that undergo inspection. In other words, results (whichpreferably include a defect report and/or a baseline) from theinspection of candidate airplanes using a particular NDI system iscompared to the gold body database developed for that NDI system and forthe particular model of the candidate airplanes.

A step 1406 includes repairing or monitoring defects detected on theplurality of candidate airplanes as will be explained in greater detailin connection with FIGS. 23 and 24.

Preferably on a parallel track to step 1406, a step 1408 is performedand includes conducting a trend analysis by analyzing collective defectdata obtained from the inspection of plurality of candidate airplanes.Trend analysis includes at least one analysis selected from a groupconsisting of applying Boolean logic rules, tracking categories ofdefects found in a component or a sub-component of the plurality ofcandidate airplanes through an overlay of images obtained from one ormore systems selected from a group consisting of an X-ray system, anN-ray system and a laser UT inspection system, tracking single sitedefect location or multi-site defect locations, tracking defectdimension, tracking growth of defect over a period of time, tracking lowobservable coatings on plurality of candidate airplanes, tracking paintdeficiencies on plurality of candidate airplanes, applying Boolean logicrules, and conducting statistical analysis. In preferred embodiments,trend analysis of the present invention assigns a defect detected to oneof the candidate airplanes by associating that defect with at least oneitem selected from a group consisting of airplane manufacturer, airplanetype, airplane model, airplane tail number, airplane part noun, airplanepart serial number, and airplane component or sub-component location bynumber. More details regarding trend analysis have been provided aboveand are also provided below in a discussion relating to FIG. 22.

In a preferred embodiment, inventive process 1400 concludes with a step1410 which involves maintaining an airplane fleet by performingpredictive analysis, which uses results of trend analysis that wasconducted in step 1408. Predictive analysis includes at least oneanalysis selected from a group consisting of applying Boolean logicrules, projecting remaining life of components or sub-components of saidplurality of candidate airplanes, projecting remaining life of saidplurality of candidate airplanes, projecting when said components orsaid sub-components of said plurality of candidate airplanes should beremoved from service, projecting load limitations for said components orsaid sub-components of said plurality of candidate airplanes, projectingneeded maintenance cycles for said plurality of candidate airplanes andprojecting spare parts inventory demand for said plurality of candidateairplanes, projecting needed maintenance resources during maintenancecycles for the plurality of candidate airplanes.

In certain embodiments of the present invention, Boolean logic rules areapplied to conduct trend analysis on a plurality of candidate airplanes,which belong to an in-service airplane fleet. By way of example, forcandidate airplanes in an F-15C airplane fleet, X-ray and N-ray roboticinspection systems and methods are used to inspect a left and a righthorizontal stabilizer's leading edge box to detect defects. A sum ofdetected defects for each type of defect (i.e., adhesive crack, blowncore, cell corrosion, crack, damaged core, moisture, skin corrosion,void, etc.) and their respective locations on the X and Y coordinatesfrom the origin are recorded. Next, results by type and location ofdefects are overlaid on a digital simulated image of the airplane's leftand right horizontal stabilizers, allowing a visual identification andstatistical analysis of trends for engineering analysis. In preferredembodiments of the present invention, additional steps follow the stepof forming digital simulated image of the airplane's component orsub-component. For example, a step of monitoring airplane fleetcondition and identifying fleet trends, as they relate to defects, flawsand deficiencies present in a region of a component or a sub-component,are carried out. As another example, a step is carried out toautomatically electronically transmit data, digital image andstatistical analysis to engineering computer systems for engineeringanalysis. In other embodiments of the present invention, certain data,digital image and statistical analysis is sent to a governmentalregulatory body (e.g., Federal Aviation Administration) to meetregulatory reporting requirements.

According to preferred embodiments of the present invention, Booleanlogic rules may also be used for conducting a predictive analysis. Inthe above example, overlaying certain defect properties on the digitalsimulated image and statistical analysis of the left and right leadingedge box allows for certain types of predictive analysis, such asdetermination of need to ground fleet, restrict fleets' operationalthreshold, and determination of maintenance cycle for the fleet (e.g.,every 6 months or 12 months), based on engineering analysis.

Those skilled in the art will appreciate that the above example of F-15Cis similarly applied to an F-35A fleet, where a laser UT roboticinspection system is used for inspecting a right wing leading edge ofcandidate airplanes in the F-35A airplane fleet. Predictive analysis andtrend analysis for the F-35A airplane fleet is carried out in a mannerthat is very similar to those described above for the F-15C airplanefleet.

FIG. 15 shows a process flow diagram for a process 1500, according to apreferred embodiment of the present invention, for developing a goldbody database. Process 1500 includes a step 1502 which includes locatinga reference airplane of a particular model in space within a roboticenvelope. By way of example, each model and series airplane is locatedto a specific spot for a nose gear and the main landing gear tires arealigned. The airplane components/sub-components may be aligned to lineson the floor. Other candidate airplanes of the same model and series,which are subsequently inspected, will also use those lines on the floorfor rough positioning. The airplane is then jacked into position usingjacks 205 (as shown in FIG. 3), taking the load off of the tires andactuators. Thus, the airplane becomes fixed in position and can nolonger move due to change in tire pressure attributed to environmentalchanges or loss of hydraulic pressure in the actuators. Edges whichdefine the boundary of the plane are taught to one or more robots usedin one or more NDI inspection systems.

Next, a step 1504 includes locating a component or a sub-component inspace within the robotic envelope such that during a subsequentinspection of candidate airplanes of the particular model, acorresponding component or sub-component in candidate airplanes isautomatically located in space using a robot. In this step, at least twoor more edges of a component or a sub-component are preferably taught toeach of the robots associated with an NDI system.

A step 1506 includes teaching a scan plan for the component of thesub-component located in space. The scan plan in this step is taught foreach NDI system that is subsequently implemented to detect defects incandidate airplanes. In this manner, process 1500 is carried out foreach NDI system that is implemented for defect detection, which in turnis carried out for effective airplane fleet management.

FIG. 17 shows an exemplar scan plan 1700 developed for a right leadingedge box (e.g., leading edge box 2604 a of FIG. 16) of a righthorizontal stabilizer (e.g., horizontal stabilizer 2604 of FIG. 16)using MNRS. Scan plan 1700 is represented in FIG. 17 in graphical form,i.e., displacement of an MNRS robot along a Y-axis 1704 versusdisplacement of the MNRS robot along an X-axis 1702. In step 1506 ofFIG. 15, scan plan like the one shown in FIG. 17 is taught to an MNRSrobot and the taught information is saved as part of the gold bodydatabase. Lines 1706 represent a path of movement traced by the MNRSrobot, as it scans the right leading edge box during inspection. Thoseskilled in the art will appreciate that scan plan 1700 is an exemplargraphical representation of the MNRS robot's plan of movement during asubsequent inspection process and that a scan plan is created for eachor critical components and/or sub-components of a candidate airplane.

FIG. 18 shows another exemplar scan plan 1800 developed for a rightleading edge box (e.g., leading edge box 2604 a of FIG. 16) of a righthorizontal stabilizer (e.g., horizontal stabilizer 2604 of FIG. 16)using MXRS, as opposed to using MNRS as described in connection withFIG. 17. Like scan plan 1700, scan plan 1800 also is represented in FIG.18 in a graphical form, i.e., displacement of a MXRS robot along aY-axis 1804 versus displacement of the MXRS robot along an X-axis 1802.Scan plan 1800 is also taught to the MXRS robot and is saved as part ofthe gold body database. Lines 1806 represent a path of movement tracedby the MXRS robot, as it scans the right leading edge box duringinspection.

Scan plans are different for each robotic imaging method such as forN-ray, X-ray or laser UT because of the field of view and the area ofinterest due to the type of airplane structure. Nonetheless, the X andY-axis coordinates on the component/sub-component or panel remains thesame. As will be explained later, this allows the results of eachinspection method (e.g., X-ray, N-ray, Reverse Geometry and laser UT) tobe identified on a master layout, allows overlaying results of theinspections to identify multi-site damage and allows downloading theresults of each airplane inspected to overlay on the same component,sub-component or panel for determining trend analysis and model airplanefleet condition.

Use of scan plans facilitates automatic inspection of airplane fleets.By way of example, once the whole airplane has been taught to the systemof the present invention, the scan plans of each NDI method can beapplied in part or whole on candidate airplanes to carry out inspection.

Inspection of a component or a sub-component using a particular NDIsystem produces, among other things, a defect report for that componentor sub-component and for that particular NDI system. A defect reportcontains at least one item selected from a group consisting of categoryof defect, defect location and defect dimensions. Defect location ispreferably a location of defect in (x, y) coordinates of the inspectedcomponent or sub-component. A defect map may be formed for a componentor sub-component by aggregating one or more defect locations. The defectmap so formed is associated with the particular NDI system used fordefect detection.

Two or more defect maps, each generated from a different NDI system, mayoverlay on a single map to produce an integrated map, which serves as ahistorical record for that component or sub-component. FIG. 19 shows anintegrated defect map 1900 produced from overlaying two defect mapsproduced by inspection of a right leading edge box of a right horizontalstabilizer using MXRS and MNRS. Integrated map 1900 is a graphicalrepresentation as it shows location of defects by referring to theirlocations on the X-axis and Y-axis. As shown in FIG. 19, integrated map1900 has defined thereon shape 1906 of the inspected sub-component,i.e., a right leading edge box of a right horizontal stabilizer. Insideshape 1906, one or more defects are presented. Integrated map 1900preferably also presents a legend to convey the meaning of one or moresymbols or letters placed at a defect location. By way of example, atone defect location 1908, which is labeled “M” and “m” and hascoordinates of about (−5,−5), both MNRS and MXRS inspections convey thatmoisture is present at that location.

FIG. 20 shows a volumetric X-ray or N-ray imaging configuration 2000,which may be used to provide a baseline image obtained during componentand/or sub-component inspection. In this configuration, a radiationimaging source 2004, which can be an X-ray imaging source or an N-rayimaging source, is used to inspect a sub-component 2002. Radiationsource 2004 is positioned on one side of sub-component 2002 such that abeam of radiation is incident upon the sub-component during an imagingprocess. A radiation source detector 2006 disposed on the other side ofsub-component 2002 detects the radiation that is transmitted through thesub-component. During a volumetric measurement process to create athree-dimensional image of a defect, radiation source 2004 articulatesaround a tool point 2008.

Volumetric measurement, according to one embodiment of the presentinvention, is accomplished by precise robotic articulation. Preciserobotic articulation is accomplished by having a robot rotate 360degrees in a circle about a tool point, causing both radiation source2004 and detector 2006 to similarly rotate.

Certain embodiments of the present invention include two dimensional(“2D”) and three dimensional (“3D”) data capture and imaging inspectionmethods and technologies. Data identifying the size of the defect ordiscrepancy is captured in the X-axis, Y-axis and Z-axis. Analog filmand digital images capture and show the defect or discrepancy in X and Ycoordinates. Once the defect or discrepancy is identified the system iscapable of articulating in a circle about the defect tool point orobject capturing an image of the tool point or object at a minimum of 8imaging stations or at least every 45 degrees on the circle. 3D imagesmay be reconstructed by articulating in a circle about the defect toolpoint or object capturing an image of the tool point or object at aminimum of 16 imaging stations or at least every 22.5 degrees on thecircle. Adjacent imaging stations images are then super imposed toprovide a 3D image. Computer generated reconstruction of multiple imagesis used to generate a laminography image. The defect or discrepancy'slocation within a component is identified by X-axis, Y-axis and Z-axisdistance from the component's X and Y origin and the layers within whichit resides between the component's innermost layer and outermost layer.The data, film and images showing the defect's and discrepancy's sizeand location within the component is recorded with the component's partnumber and serial number, and the component is recorded at the time ofthe inspection with the airplane's tail number. The component may beused on multiple airplanes, during their life cycle, by beingdisassembled from the airplane, repaired or refurbished, and then placedinto a rotational spares inventory for use on any airplane undergoingmaintenance and repair.

Display of images is accomplished utilizing 2D and 3D front or rearprojection screens, displays and monitors. The viewer may wear activeshudder glasses or passive Polaroid glasses when viewing projectionscreens, display and monitors requiring these eyewear devices. X-ray andN-ray scan plans are modified to accomplish this task. These methods maybe utilized when capturing and viewing real time or offset images, suchas volumetric measurement that detects and provides data and imagecapture of the length, width and depth of a defect or discrepancy instructural material. The data and image capturing and viewing methodsare commonly used in the inspection of airplane components comprised ofmulti-layered metal and composite structural material. This methodidentifies defect and discrepancy size and location to monitor componentmaintenance, assist implementation of pre-repair procedures and repairtechnologies, and validate post repair procedures.

FIG. 21A shows a comparison between two components defect maps, one mapfor a left and another map for a right horizontal stabilizer (e.g., mapfor left horizontal stabilizer 1604 juxtaposed to a map for righthorizontal stabilizer 2604 shown in FIG. 16). The component defect mapshows a left region 2102 in a left leading edge of the left horizontalstabilizer and a corresponding right region 2104 in a right leading edgeof the right horizontal stabilizer. Left region 2102 includes moisturedefects, which are not found in the corresponding right region 2104.While not wishing to be bound by theory, presence of such defects in oneregion and absence of them in a second region convey that they aremanufacturing defects. As a result, defect analysis of the presentinvention provides a feed-back loop to the manufacturing processregarding the amount and types of defects being introduced duringmanufacturing, and the repair process will be different.

FIG. 21A shows, among other things, results of mobile airplaneinspection, and the comparison of findings of left and right horizontalstabilizer components. It is noteworthy that defect locations are notsimilar in comparison. According to preferred embodiments of the presentinvention, engineering disposition investigates and determines whycertain defects, such as fatigue, defects from use of impropermaterials, and defects resulting from manufacturing and assemblyprocess, exist or exist in one region, but not in another correspondingregion.

FIG. 21B is a tabular representation of summary of defects found in aright horizontal stabilizer. The summary of defects is broken down intosub-components, having those that are disposed on the left sidejuxtaposed with those that are on the corresponding right side of theairplane. Furthermore, for each sub-component, number of defects thatbelong to a particular defect category (e.g., adhesive crack, blowncore, cell corrosion, crack, damaged core, moisture, skin corrosion andvoid) are also tracked and summarized. Further still, summary of defectsalso informs regarding the number of defects found by MXRS inspection(shown in FIG. 21B as “MX”) and by MNRS inspection (shown in FIG. 21B as“MN”). As an example, FIG. 21B shows that the number of corroded cellsfound in the left aft box using MXRS is 13, and using MNRS is 3. It isbelieved that a significant difference in the results between MXRS andMNRS inspection allows for various possible conclusions, all of whichinform the manufacturing and repair process.

FIG. 22 presents an exemplar trend analysis of 50 airplanes of anairplane fleet. All the various components and sub-componentstherewithin are presented along a left column, and in the remainingcolumns an analysis is presented for ten, twenty, thirty, forty andfifty airplanes. As an example, a trend analysis for forty airplanesidentifies the defect components. With regard to wing components, trendanalysis shows that 30% of the flaps, 85% of ailerons and 43.8% of thewing tips are defective. Similarly for horizontal stabilizers, trendanalysis shows 66.3% of aft boxes and 75% of leading edge boxes aredefective. For vertical stabilizers, trend analysis shows that 50% offorward boxes, 30% of torque boxes, and 55% of aft boxes are defective.As mentioned above, for each component and/or sub-component, FIG. 21Bprovides the types of defects found in the components/sub-components.With regard to the aft and leading edge boxes of a horizontalstabilizer, FIG. 21B shows that defects are primarily moisture sites andskin corrosion.

As mentioned before, trend analysis allows monitoring airplane fleetcondition and identifying fleet trends, as they relate to defects, flawsand deficiencies present in a region of a component or a sub-component.Such analysis is based on developing results by type and location ofdefects. Where an airplane's horizontal stabilizers are the component ofconcern, it has been explained that these results may be overlaid on adigital simulated image of the left and right horizontal stabilizers,allowing a visual identification and statistical analysis of trends forengineering analysis. Boolean logic rules, which may be applied on typeof defect, defect severity, and defect frequency (a statisticallymonitored condition), facilitate prediction or, in the alternative,projection of maintenance activities to effectively manage an airplanefleet. Maintenance activities of the present invention include, but arenot limited to, grounding an airplane fleet, restrict a fleet'soperational thresholds that govern flight loads, and electronicallytrigger maintenance planning, execution, and reporting. In otherembodiments of the present invention, Boolean logic rules determine arecommended inspection frequency to monitor the fleet's defect condition(e.g., defect growth), and/or maintenance or repair treatment plan.

The following Boolean logic algorithm is based on the results of trendanalysis and represents an example of maintenance and treatment planimplemented according to the present invention for an in-service F-15Caircraft fleet (referred to as “F-15C Fleet” below):

-   -   If F-15C Fleet LHS SC> or =5, and if ML>8%, then F-15C Fleet LHS        TCTO XI and NI=12 and ALC-I99061-02; and if ML<8%, then F-15C        Aircraft LHS ALC-R890444-01; and if ML>8%, then F-15C Aircraft        LHS ALC-RR890526-01; and if ML>10%, then F-15C Aircraft T=80%;        and then F-15C Fleet XI and NI=60 and ALC-M890538-00;    -   If F-15C Fleet LHS SC<5, if ML<8%, then F-15C Aircraft        ALC-R890444-01 and if ML>8%, then F-15C Aircraft LHS        ALC-RR890526-01, and if ML>10%, then F-15C Aircraft T=80%, and        then F-15C Fleet XI and NI=60 and ALC-M890538-00.

According to this algorithm, if skin corrosion (which is denoted by “SC”above) is detected in a left horizontal stabilizer (“LHS”) in 10% ormore of 50 F-15C aircrafts (“F-15C aircrafts”) belonging to thein-service F-15C aircraft fleet, then different recommended actions arepossible for the airplane fleet and a particular airplane, depending onresults of different defect measurements. If material loss (“ML”) isgreater than 8% for the entire fleet, then an inspection by X-rayinspection (“XI”) and N-ray inspection (“NI”) for the entire F-15Caircraft fleet is scheduled to occur within 12 months under a TimeCompliant Technical Order (“TCTO”), and pursuant to treatment planALC-I99061-02. If a material loss is less than 8%, however, then for theF-15C aircraft, which satisfies the material loss condition, aninstruction is provided to repair the moisture intrusion entry path inthe left horizontal stabilizer pursuant to ALC-R890444-01.

For a particular aircraft, which suffers from a material loss that isgreater than 8%, then left horizontal stabilizer is scheduled for repairand replacement pursuant to treatment plan ALC-RR890526-01. Furthermore,if the material loss for that aircraft measures greater than 10%, aninstruction is provided to reduce in-flight operational threshold thrust(“T”) of that aircraft to 80% of maximum performance until F-15Caircraft completion of left horizontal stabilizer's replacement. Forthis material loss condition, after left horizontal stabilizer repairpursuant to treatment plan ALC-R890444-01 or replacement and repairpursuant to treatment plan ALC-RR890526-01, as the case may be withinthe twelve-month maintenance cycle, an inspection by X-ray inspection(“XI”) and N-ray inspection (“NI”) for the entire F-15C aircraft fleetis scheduled to occur thereafter in sixty months pursuant to treatmentplan ALC-M890538-00.

In the same example, if skin corrosion is detected in the lefthorizontal stabilizer in less than 10% of 50 aircrafts of the F-15Caircraft fleet, and if material loss for the F-15C aircraft fleet isless than 8%, then an instruction is provided to repair the moistureintrusion entry path in the left horizontal stabilizer of each detectedF-15C aircraft pursuant to ALC-R890444-01. For a particular F-15Caircraft, which suffers from a material loss that is greater than 8%,then left horizontal stabilizer is scheduled for repair and replacementpursuant to treatment plan ALC-RR890526-01. Furthermore, if the materialloss for that aircraft measures greater than 10%, an instruction isprovided to reduce in-flight operational threshold thrust (“T”) of thataircraft to 80% of maximum performance until completion of lefthorizontal stabilizer's replacement. For this material loss condition,after left horizontal stabilizer repair pursuant to treatment planALC-R890444-01 or replacement and repair pursuant to treatment planALC-RR890526-01, as the case may be within the twelve-month maintenancecycle, an inspection by X-ray inspection (“XI”) and N-ray inspection(“NI”) for the entire F-15C aircraft fleet is scheduled to occurthereafter in sixty months pursuant to treatment plan ALC-M890538-00.

Treatment plans ALC-I99061-02, ALC-R890444-01, ALC-RR890526-01, andALC-M890538-00 consist of digital code-driven tables. Such tablestypically consist of airplane repair station procedures and processesnecessary for inspection, maintenance, and repair. Furthermore, suchtables may also contain digital sub-tables of required and interrelatedrepair station resources. Examples of interrelated repair stationresources include, but are not limited to, facilities, equipment,manpower, man-hours, service-time, and direct and indirect costs and theutilization sequence of same in the inspection, maintenance, and repairprocess.

By way of example, a table-driven procedure for ALC-RR890526-01, whichmay be automatically selected when implementing Boolean logic rules,includes: (a) identifying repair procedures and/or develop new oradditional procedures; (b) identifying direct and indirect materialsneeded for repair; (c) identifying any special tooling and equipmentneeded for the repair; (d) identifying or determine mechanic,technician, and specialist repair team certifications and training needsto satisfy repair procedures; (e) scheduling prototype development onrepair procedures; (f) identifying or develop technical data for theprocesses; (g) identifying amount of spares available in supply; (h)inspecting spares as in Example 1A for defects; (i) repairing deficientspares in preparation as a replacement part; (j) Re-inspecting allrepaired spares for proper repair; (k) identifying or determine repairtimeline for scheduling of resources; (l) scheduling facility,equipment, inventory, materials, and human resources required; (m)scheduling airplane fleet for induction into repair at repair station;(n) projecting repair budget; (o) inducting the airplane fleet forhorizontal stabilizer repair; (p) repairing dismantled left or righthorizontal stabilizer; (q) inspecting repaired left or right horizontalstabilizer for defects before placing it into spares inventory.

FIG. 23A shows a process 2300, according to a preferred embodiment ofthe present invention, for airplane inspection which requires removal ofa defective component or sub-component. In this embodiment, inventiveprocess 2300 begins with a step 2302. Step 2302 includes locating acandidate airplane, which will be subject to inspection by one or moreNDI systems, in space within a robotic envelope. Next, a step 2304includes locating a component or a sub-component of the candidateairplane in space within the robotic envelope.

Once the airplane and the component or the sub-component is located inspace, one or more NDI systems are in position to commence a scanningstep. A step 2306 includes scanning the component or the sub-componentaccording a scan plan developed for that component or thatsub-component. As mentioned above, each robot associated with an NDIsystem is taught a scan plan (e.g., step 1506 of FIG. 15) during aprevious process of forming a gold body database.

A step 2308 includes identifying defects to generate a defect report(e.g., presenting category, location and dimensions of each defect) forthe component or the sub-component, and/or to develop a baseline for thecomponent or the sub-component. In a following step 2310 it is inquiredwhether there are any defects which need to be repaired. As mentionedbefore, defects are preferably evaluated against a predeterminedaccept/reject criteria to determine corrective maintenance and repairactions

If it is determined that none of the defects identified need to berepaired, then process 2300 moves to a step 2312, which includesmonitoring the defects over a period of time when inspections such asthe ones described above are carried out. Monitoring includes trackingdefects growth in length, width and depth.

If, however, it is determined that one or more defects need to berepaired, then process 2300 moves to a step 2314, which includesremoving from the airplane the component or the sub-component that needsto be repaired. After step 2314, various steps involved in process 2300are presented in FIG. 23B.

According to FIG. 23B, a step 2316 follows step 2314 (of FIG. 23A) andincludes repairing the component or the sub-component to remedy thedefect(s). Next, a step 2318 includes developing an “off-the-airplane”scan pan for the repaired component or the repaired sub-component andstoring on a database the off-the-airplane scan plan such that it isassociated with a serial number of the repaired component or therepaired sub-component. An “off-the-airplane” scan plan looks similar tothe scan plans shown in FIGS. 17 and 18. However, as the name suggests,an “off-the-airplane” scan plan is developed when a component or asub-component is off the airplane. Then, a step 2320 is carried out andincludes inspecting the component or the sub-component to determine ifthe defect was repaired properly.

A step 2322 inquires whether the defect was repaired properly. If it isdetermined that the defect was not repaired properly, then process 2300goes back to step 2316, where repairs are carried out again. Steps 2318,2320 and 2322 follow the repair step of 2316. In this manner, steps2316, 2318, 2320 and 2322 may be carried out, according to a loop shownin FIG. 23B, until the defects are repaired properly.

If, however, it is determined that the defect was repaired properly,then process 2300 moves forward to a step 2324, where another inquiry ismade. In step 2324, it is inquired whether the properly repairedcomponent or the properly repaired sub-component should be installed onthe airplane at this point. In other words, step 2324 inquires whetheranother component or sub-component should be installed on the candidateairplane, instead of installing the repaired component or the repairedsub-component. Such an inquiry may be made for a variety of reasons. Byway of example, if the repair process is long and time-consuming,another component or sub-component from inventory is installed on thecandidate airplane so that the candidate airplane is back to beingfunctional in short order.

If it is determined in step 2324 that that the repaired component orsub-component should be installed at that point on the candidateairplane, then process 2300 moves to a step 2332, which requiresinstalling the repaired component or repaired sub-component on theairplane. Next, in a step 2334 the newly developed scan plan for therepaired component or the repaired sub-component is incorporated intothe overall scan plan for the airplane. In preferred embodiments of thepresent invention, step 2334 is carried out by assigning a scan plandeveloped for the repaired component or repaired sub-component to thetail number of a candidate airplane.

If it is determined in step 2324 that that the repaired component orsub-component should not be installed at that point on the candidateairplane, then process 2300 moves to a step 2326, which requires holdingthe repaired component or the repaired sub-component as inventory. Next,in a step 2328 the repaired component or the repaired sub-component isinstalled on another airplane, which is different than the airplane fromwhich the component or the sub-component was removed, as mentioned instep 2314 of FIG. 23A.

A step 2330 includes incorporating the newly developed scan plan for therepaired component or the repaired sub-component in the overall scanplan for the airplane in which the repaired component or the repairedsub-component is installed. As a result, for subsequent inspection ofthe airplane, there exists an updated gold body database to effectivelyidentify defects.

FIG. 24A shows a process flow diagram for a process 2400, according toone preferred embodiment of the present invention, for an airplaneinspection, which does not require removal of a defective component orsub-component.

Process 2400 preferably begins with a step 2402 which includes locatinga candidate airplane, which will be subject to inspection by one or moreNDI systems, in space within a robotic envelope. In step 2402, anairplane offset is arrived at by comparing a current location of theairplane to a reference location of the airplane. The reference airplanelocation is preferably stored as part of the airplane's gold bodydatabase. The offset preferably represents a difference between acurrent location of the airplane to the reference location of theairplane.

Next, a step 2404 includes locating a component or a sub-component ofthe candidate airplane in space within the robotic envelope. Like step2402, step 2404 also arrives at an offset. However, in step 2404 theoffset may be called a “component offset” or a “sub-component offset,”as it results from the comparison between the current location of thecomponent or the sub-component and the reference location of thecomponent or the sub-component stored in the gold body database.

A step 2406 is then carried out to scan the component or thesub-component according to a scan plan developed for that component orthat sub-component, such that the scan plan compensates for thecomponent offset or the sub-component offset. In other words, the scanplan is initiated when the reference points (i.e., the zero-zerocoordinates) of the component or the sub-components located in space areestablished from the component or the sub-component offsets.

Next, a step 2408 includes identifying defects to generate a defectreport (e.g., presenting category, location and dimensions of eachdefect) for the component or the sub-component, and/or to develop abaseline for the component or the sub-component. The defect reportand/or baseline obtained from step 2408 is archived in step 2410 so thatat a later time, it is possible to conduct a trend analysis on datacollected from a plurality of airplanes, or conduct a base linecomparison for the component or the sub-component. After step 2408, itis inquired whether there are any defects which need to be repaired.

If it is determined that none of the defects identified need to berepaired, then process 2400 moves to a step 2414, which includesmonitoring the defects over a period of time when inspections such asthe ones described above are carried out.

If, however, it is determined that one or more defects need to berepaired, then process 2400 moves to a step 2416 (shown in FIG. 24B),which includes repairing the component or the sub-component to remedythe defect(s). Next, a step 2418 is carried out and includes inspectingthe component or the sub-component to determine if the defect wasrepaired properly.

A step 2420 inquires whether the defect was repaired properly. If it isdetermined that the defect was not repaired properly, then process 2300goes back to step 2416, where repairs are carried out again. Steps 2418and 2420 follow the repair step of 2416. In this manner, steps 2416,2418 and 232 may be carried out, according to a loop shown in FIG. 24B,until the defect(s) are repaired properly.

If, however, it is determined that the defect was repaired properly,then process 2400 may conclude at a step 2422 which includes storing ona database results of the scan plan of the airplane's overall scan plan.In preferred embodiments of the present invention, step 2422 is carriedout by assigning the scan plan to a tail number of the airplane.

In certain embodiment of the present invention, once a repairedcomponent passes post inspection (i.e., the inquiry in steps 2322 (ofFIG. 23) and 2420 (of FIG. 24) are answered in the affirmative),archival data and images are assigned and recorded to that specificcomponent by the component's part and serial numbers, and by the tailnumber of the airplane on which it is installed. Cradle to graveidentification of all inspected components, by intact airplane systemsor component systems, are archived and indexed by tail number, partnumber and serial number. Spare parts are inspected prior toinstallation and eventually identified and indexed to specific airplanetail number.

It is noteworthy that candidate airplanes, undergoing inspection, arenot absolutely required to be jacked in place for stabilization. In suchinstances, the airplane may be located within the robotic envelope tothe line markings on the floor plus or minus eight inches. The robotthen seeks to locate the vision edges on the airplane. Once located, therobot automatically recognizes where the taught airplane was inreference and where follow-on production airplane is located. Asexplained above, this is called an offset and is transparent to systemoperators. Scan plan accuracy is preferably about 0.120 thousands of aninch on all production airplanes. Given that no two airplanes areexactly the same, a system operator can manually align the robot byjoystick control to the beginning zero-zero coordinates on each andevery component or sub-component, allowing about 0.120 thousands ofaccuracy of scan for each component or each sub-component from airplaneto airplane. For precise measurement and evaluation of defects, manualalignment can also be accomplished by aligning to a particular defect.

This description of the disclosed aspects of the present invention isprovided to enable any person skilled in the art to make or use thepresent invention. Various modifications to these aspects will bereadily apparent to those skilled in the art, and the generic principlesdefined herein may be applied to other aspects without departing fromthe spirit or scope of the invention. Moreover, having thus describedthe invention, it should be apparent that numerous structuralmodifications and adaptations may be resorted to without departing fromthe scope and fair meaning of various embodiments of the instantinvention as set forth hereinabove and as described herein below by theclaims.

What is claimed is:
 1. A method for managing an airplane fleet, saidmethod comprising: developing a gold body database for an airplane modelfor each non-destructive inspection system implemented to detectdefects; inspecting, over a period of time, a plurality of candidateairplanes of said airplane model, using different types ofnon-destructive inspection systems and said gold body databaseassociated with each of said different types of non-destructiveinspection systems, to identify defects present on said plurality ofcandidate airplanes; repairing or monitoring defects detected on saidplurality of candidate airplanes; conducting a trend analysis byanalyzing collective defect data obtained from said inspecting of saidplurality of candidate airplanes; and maintaining said airplane fleet,which includes said plurality of candidate airplanes, by performingpredictive analysis using results of said trend analysis.
 2. The methodof claim 1, wherein said non-destructive inspection systems is at leastone system selected from a group consisting of X-ray inspection system,N-ray inspection system and laser ultrasonic inspection system.
 3. Themethod of claim 2, wherein said X-ray inspection system inspects for atleast one defect selected from a group consisting of moisture,corrosion, cracks, fatigue damage, collateral damage, flaws,deformation, and foreign objects.
 4. The method of claim 2, wherein saidN-ray inspection system inspects for at least one defect selected from agroup consisting of internal moisture, corrosion, internal fuel leaks,and voids in sealants.
 5. The method of claim 2, wherein said laserultrasonic inspection inspects for at least one defect selected from agroup consisting of disbond, delamination, impact damage, material life,porosity and voids.
 6. The method of claim 1, wherein said inspecting iscarried out at an inspection facility, which includes a roboticenvelope, and said repairing is carried out at a repair facility, whichis different from said inspection facility.
 7. The method of claim 1,wherein said inspecting further comprises: identifying critical defects;and articulating around a tool point at or near a location of at leastone of said critical defects to obtain a volumetric measurement of saidat least one of said critical defects.
 8. The method of claim 1, whereinsaid articulating around said tool point includes imaging one of saidcritical defects from eight different locations.
 9. The method of claim1, wherein said maintaining said fleet includes keeping in a supplyfacility spare parts for components or sub-components of said pluralityof candidate airplanes, as each of said spare parts are waitingassignment to a specific airplane tail number.
 10. The method of claim1, wherein said trend analysis includes at least one analysis selectedfrom a group consisting of tracking categories of defects found in saidcomponent or sub-component of said plurality of candidate airplanesthrough an overlay of images obtained from one or more systems selectedfrom a group consisting of an X-ray system, an N-ray system and a laserultrasonic inspection system, tracking single site defect location ormulti-site defect locations, tracking defect dimension, tracking growthof defect over a period of time, tracking low observable coatings onsaid plurality of candidate airplanes, tracking paint deficiencies onsaid plurality of candidate airplanes, applying Boolean logic rules, andstatistical analysis to determine fleet condition and defect trends. 11.The method of claim 1, wherein said trend analysis assigns a defect toone of said plurality of candidate airplanes by associating said defectwith at least one item selected from a group consisting of airplanemanufacturer, airplane type, airplane model, airplane tail number,airplane part noun, airplane part serial number, and airplane componentor sub-component location by number.
 12. The method of claim 1, whereinsaid repairing is carried out by removing components or sub-componentsfrom said plurality of candidate airplanes and then repairing saidcomponents or said sub-components, or repairing said components or saidsub-components in their assembled configuration on said plurality ofcandidate airplanes.
 13. The method of claim 1, wherein said predictiveanalysis includes at least one analysis selected from a group consistingof applying Boolean logic rules, projecting remaining life of componentsor sub-components of said plurality of candidate airplanes, projectingremaining life of said plurality of candidate airplanes, projecting whensaid components or said sub-components of said plurality of candidateairplanes should be removed from service, projecting load limitationsfor said components or said sub-components of said plurality ofcandidate airplanes, projecting needed maintenance cycles for saidplurality of candidate airplanes and projecting spare parts inventorydemand for said plurality of candidate airplanes.
 14. The method ofclaim 13, wherein said applying Boolean logic rules provides predictinga next maintenance cycle.
 15. The method of claim 1, wherein saidinspecting includes generating a defect report, which presents at leastone item selected from a group consisting of category of defect, defectlocation, defect count and defect dimensions, defect statisticalanalysis, and said defect report being generated for each component orsaid sub-component of each candidate airplane subject to saidinspecting.
 16. The method of claim 20, wherein said defect location isa location of a defect in (x, y) coordinates of said component or saidsub-component.
 17. The method of claim 16, further comprising:aggregating one or more defect locations to form a defect map for saidcomponent or said sub-component for each said non-destructive inspectionsystem implemented; overlaying said defect maps produced from each saidnon-destructive inspection system implemented for said component or saidsub-component to produce an integrated defect map, which is used ashistorical record for said component or said sub-component.
 18. Themethod of claim 17, further comprising taking an image of said defect insaid (x, y) coordinates of said component or said sub-component toproduce a defect image to facilitate one process selected from a groupconsisting of repairing said defect, monitoring said defect andsubjecting said defect to engineering disposition.
 19. The process ofclaim 18, further comprising associating said defect image with a tailnumber of one of said candidate airplane.
 20. A system for managing anairplane fleet, said system comprising: means for developing a gold bodydatabase for an airplane model for each non-destructive inspectionsystem implemented to detect defects; means for inspecting, over aperiod of time, a plurality of candidate airplanes of said airplanemodel, using different types of non-destructive inspection systems andsaid gold body database associated with each of said different types ofnon-destructive inspection systems, to identify defects present on saidplurality of candidate airplanes; means for repairing or monitoringdefects detected on said plurality of candidate airplanes; means forconducting a trend analysis by analyzing collective defect data obtainedfrom said inspecting of said plurality of candidate airplanes; and meansfor maintaining said airplane fleet, which includes said plurality ofcandidate airplanes, by performing predictive analysis using results ofsaid trend analysis.
 21. The system of claim 20, wherein said means fordeveloping a gold body database includes a non-destructive inspectionsystem which includes one or more inspection systems selected from agroup consisting of X-ray inspection system, N-ray inspection system andlaser ultrasonic inspection system.
 22. The system of claim 20, whereinsaid trend analysis and said predictive analysis is carried out using acomputer.
 23. The system of claim 20, wherein said repair is carried outusing laser ablation.